Marine edifice



March 17, 1953 R. WHITE MARINE EDIFICE 2 SHEETS-SHEET 1 Filed Aug. 4.1947 I i a IE. R

a E ww INVENTOR:

. Ross WHIT W3 mm A T TORNEY March 17, 1953 R. WHITE MARINE EDIFICE 2SHEETS-SHEET 2 Filed Aug. 4. 1947 INVE-NTOR: Ross WHITE BY 2 Z 2ATTORNEY Patented Mar. 17, 1953 MARINE EDIFICE Ross White, Houston,Tex., assignor to Brown and Root, Inc., Houston, Tom, a corporation ofTexas Application August l, 1947, Serial-No. 765,857

1 Claim. 1

This invention pertainsto a marine; edifice suitable for a base ofoperations, particularly .marine construction operations such asoffshore drilling for petroleum'.

Thejprincipal' object of the invention is to make it possible.- to carryonsuch operations during all types of weather excepting hurricanes andstorms of likeseverity.

It is, a further object of the invention to minimizethe dangers to lifeand property of such operations.

A still further object of the invention is to reduce the costof suchoperations.

Briefly described, the invention contemplates the provision of a. smallstationary platform supported .outof the water on piling, from whichplatform operations such as drilling .an under water well hole. may be.carried on. At a considerable distance from the. platform a tower iserectedv out of the Water and betweenthis tower and, .a. similar towermounted on or near the main platform there will be mounted a highline onwhich an ordinary cable. car can be suspended and operated to move backand forth between the towers and up and down beneath the highline.Between the main platform and the tail tower for the highline a largefloating vessel is moored. Preferably, the vesselis moored with its bowin the direction ofv the prevailing wind, the mooring being adjustablefrom the vessel to take care of minor shifts in the wind so that thevessel can always be made to face directly into the wind. The vesselshould be ofsuch length that itwil-l span the distancebetween Wavecrests of any ordinary waves which areencountered in the area where theconstruction is to be carried on. By the term ordinary waves is meantsuch waves'as occur during ordinary weather, rough as Well as calm, butexcluding hurricanes and storms of like severity." Usually such waveswill not be overtwo hundredfeet long.

On board the floating vessel are carried all the necessary supplies andpersonnel needed for carrying on the marine construction. Bothtmen andmaterials are transferred to the working platform asneeded by. means ofthe cable car. Certain fluid materials such aswater, fuel oil anddrilling: mud: may be transferred from the'fioating vessel to the main:platform by means of underwater pipes connected to the vessel byflexible users.

The advantages ofjthe-invention as just de scribed can most easilybepointed out by comparisonwith anotherproposed form of operating base foroffshore drilling comprising a fixed plat.- form; which large enough tocarry not only 2 the dri11ing rig but also a substantial quantityof'materials and equipment such as pipe and mud and also to provide apermanent living quarters for the workmen. Such an arrangement has ahigh initial cost and a low salvage value when the drilling operation iscompleted. In addition there is a great risk of loss or serious damageto the platform and the equipment thereon-during conditions of badweather, for the entire platform being immobile is exposed: to the fullforce of the wind and sea at all times. Offshore drilling conducted oneven the largest fixed platform which can be economically constructed isnot a self-sufficient operation and the platform must be continuallysupplied with pipe, drilling mud, fuel oil, and provisions from shore'bysmall boats or barges. Thissupply may be interrupted during roughweather which makes it dangerous to personnel and equipment for smallbarges to go alongside the platform for unloading; A third disadvantageof the fixed platform system is the personnel problem. Not only are thepersonnel exposed to danger by being unable toleave the site of drillingoperations in case'of severe storm or hurricane but their quarters forliving are necessarily cramped. There is the-further problem of makingsuitable disposition of off-shift personnel in a manner so as-not toaffectthe efiiciency nor morale of the men who-are working.

All three disadvantages of the large fixed platform system of offshoredrilling are overcome by the present invention; thus since only a smallplatform is provided of just sumcient size to accommodate the derrick,draw works and high pressurepumps, together with a small supply ofequipment and. materials, it will not have. nearly the high initial'costof a large platform nor will there be as great a problem of salvagingvthe platform when the drilling operation has been completed and it isdesired to move the platform elsewhere; Since the structure need notcarry such a heavy weight of supplies a minimumof lateral bracing can beused so as to'reduce the area exposed to violent wave action. Only asingle deck'need beprovided, which can be arranged in -pan'els for rapiderection and dismantling. All large stores ofequipm'ent and'all-housingand'messing facilities and personnel willbe provided'on' the floatingvessel which may easily be. moved from one location to another whendrilling operations have been completed. In-case of. severe stormxorvhurricane the vessel canbe removed to a safe position; Such supplies andmaterial as are neede'don the platform caneasily be transferred from thefloating vessel to: the

platform by means of the cable car. This can be accomplished even inrough weather since a large vessel will have but a small rise and falldue to the fact that it bridges between waves rather than rides on anindividual wave.

For a detailed description of a preferred embodiment of the inventionreference will be had to the accompanying drawings in which- Figure 1 isan elevation of a marine edifice according to the invention, and

Figure 2 is a plan view thereof.

Referring to Figure 1 there is shown a platform l supported on pilingII. The piling is driven or otherwise placed into the ground beneath thefloor l2 of the body of water [3. Light cross braces such as thatindicated at l4 may be used to tie the piles together. Where theplatform IQ is to be used as a base from which to carry on drillingoperations a derrick [5 may be erected on the platform [0. At one sideof the platform In there is erected a tower I6.

At a considerable distance from the platform l0, perhaps 500 feet moreor less, a second tower I! is erected on piles l8 which, like the pilesH, are placed into the ground beneath the floor of the body of water l3.In some cases where drilling operations are to be carried on fairly nearto the shoreline the tower I! may be erected on dry land but in theusual case both towers will be over water.

Between the towers l6 and I! there is placed a cable way of knownconstruction which may comprise, for example, a main supporting cablefixed each end to opposite towers. A carriage 2! is supported on wheelswhich run on the cable 20. The carriage 21 can be moved back and forthalong the cable between the towers l6 and I! by means of a traversingcable 22 which passes around sheaves at the tops of the towers I6 and I1and the ends of which are both connected to the carriage 2|. A bight ofthe cable at tower 16 passes around reversible winch 23. A skip 24 issupported on a hook depending from sheave 25 which in turn is supportedfrom the carriage 2| by a hoist line 26 fixed at one end to the carriage2i and passing around the sheave 25 and a pulley on the carriage 2|. Theother end of the hoist line 26 passes through guides 2i suspended fromthe main cable 20 and thence over a sheave at the top of tower l'l downto another reversible winch 28.

Beneath the cable way there is moored a floating vessel 30. Between thevessel 30 and the platform l0 there are suitable conduits for fluidmaterials, each of which includes a flexible hose 3| connected to anunderwater pipe 32 laid on the floor 12 and a riser 33. These fluidconduits are shown in plan view in Figure 2 where by way of examplethere are shown three conduits 34, 35 and 36 for carrying low pressuremud, fuel oil, and water from the vessel 30 to the platform I0 wheredrilling operations are carried on.

Figure 2 illustrates a preferred method of mooring the vessel 30. Thevessel is connected by 4 cables 4|, 42, 43 and 44 to spring buoys 45,45, 41 and 48. The spring buoys comprise merely large buoys connected byvery heavy chains 49, 50, 5| and 52 to heavy anchors such as that shownat 53 which preferably is of the type known as the Eell anchor which hastwo long angularly disposed tapered flukes extending backward from theanchor stem. The buoys 45, 46, 41 and 48, being of large size willnormally remain out of water and the heavy chains connecting them to theBell anchors will assume the form of a catenary. In case of a suddenforce applied to the vessel by wind or wave the spring buoys will act asshock absorbers, reducing the tension on the cables 4|, 42, 43 and 44.In such case the buoys will be pulled slightly under water and thechains connecting them to the anchors will straighten out.

The cables 4|, 42, 43 and 44 pass through rotary chocks and thence topower winches such as that shown at 54. By adjusting the lengths of thecables with the winches the vessel 30 can be turned to any desiredposition within limitations depending on the geometry of the particularmooring. By this means the vessel 30 can be turned so that itslongitudinal or streamline axis is directed into the wind. The meanposition of the ship as determined by the positions of the four anchorsshould be that of the prevailing wind and the range of change ofdirection of the vessel should be sufficient to care for normalvariations of the usual wind direction.

The vessel 30 should be of small beam compared to the distance betweenthe platform [0 and the tower IT to minimize the possibility of thevessel being carried over against one of them in a storm. In addition,although the ship is of small beam compared to its length the length ofthe vessel should be substantially less than the distance between theplatform l0 and tower I! to minimize the possibility of one end of thevessel swinging over against the platform in case it breaks loose fromits moorings at one end. For example, as shown in the drawing, thevessel 30 is of a length equal to approximately twothirds the distancebetween the platform I0 and the tower I1. Since the platform [0 is thelocation of the construction work to be performed, e. g., oil welldrilling, it is particularly important that the vessel never be allowedto contact the platform [0 and for this reason additional moorings maybe provided. As shown in Figure 2 these side moorings comprise cables55, 56 which are connected to spring buoys 51, 58 similar to the springbuoys of the main 4-point mooring, each being provided with a heavychain and Bell anchor as shown at 59 and 60. The length and tension ofthe cables 55 and 56 can be changed by means of a power winch 6| towhich either of the cables can be connected through a suitable block andtackle 62 and stationary pulley 63. For additional stability the usualbow and stem anchors 64 and 65 carried on chain 66 and cable 61respectively, can be used.

The towers l6 and I! are preferably disposed so that a line drawnbetween them is at right angles to the direction of the usual wind andsea so that when the vessel 30 is moored therebetween heading into thewind the cable 20 will run athwart ship thereof. While it is usuallypreferable to place the tower IS on the platform I!) or immediatelyadjacent thereto so that the cableway operator in the tower 16 can be inimmediate communication with the workmen on the platform I0 it is withinthe purview of the invention that the tower can be placed at somedistance from the platform II). It is only necessary that the cablewaypass over the top of the platform I0.

There is also some latitude with respect to the point along the lengthof the vessel 30 at which the cableway crosses for as long as the vessel30 is of considerable length compared to the crest to-crest wave lengthof the rough sea normally encountered there will be very little pitch.However, it is preferable that the cableway 20 cross the vessel 30directly amidship, in which case the pitch of the vessel will havepractically no effect whatsoever andthe only motion noticeable will be aslight rise and fall and also perhaps a slight roll if the vessel is notheaded directly into the wind. It is because of this comparativestability of the amidship section of a large vessel that it is possibleto transfer men and materials from the skip 24 to the vessel 39 even inrelatively rough weather.

In use of the marine edifice previously described the men will be housedon the vessel 30 and all the materials required for a normal drillingoperation to the expected depth of the well will also be carried on thevessel. On the platform It there will be carried only enough men tooperate the drilling rig and the cableway. Pipe, casing, and othermaterials will be transferred to the platform from the vessel 3:: asneeded. Fluid materials will be pumped to the platform through theunderwater conduits. In case of storm all the men can be removed fromthe platform to the vessel 30 and if a hurricane or other severe stormis predicted the vessel 30 may be disconnected from its moorings andtaken to a place of shelter. For this purpose the connections betweenthe cables 4|, 42, 43 and 44 and the spring buoys is preferably made ofa quick attachable-detachable type. The flexible hose for the fluidconduits are also disconnected from the vessel, blanked off and buoyedso that re-connection can be made after the storm is over. The vessel 30is preferably self-propelled but may in some cases be merely a bargewhich is towed to and from location with a tug.

While a preferred embodiment of the invention has been shown anddescribed, many modifications thereof can be made by one skilled in theart without departing from the spirit of the invention and it isintended to cover by Letters Patent all forms of the invention fallingwithin the scope of the appended claim.

I claim:

Apparatus for conducting ofishore marine operations comprising astructure built completely off shore on the marine floor and risingabove water, a working platform supported above water on said structure,an elongated vessel, means for elastically mooring the vessel to themarine floor whereby the vessel can move without breaking loose itsmooring but is constantly restrained from motion, means on said vesselfor adjusting said mooring means to keep the vessel headed into the windwhereby to minimize rolling of the vessel, said vessel having a lengthof about two hundred feet at least whereby the vessel can span thecrests of the longest calm and normal rough weather ocean waves tominimize rise and fall and pitching of the vessel, a pair of structuresbuilt on the marine floor and rising above water, two towers supportedone on each of said pair of structures, said tower supporting structuresbeing spaced apart with said platform and the amidships section of thevessel in between and in line therewith, the distance from the amidshipssection of the vessel to the nearest one of said platform and towersupporting structures being greater than half the length of the vesselwhereby as the vessel is turned to head into the wind it will always beclear of said structures, said line between the tower supportingstructures being perpendicular to the direction of the prevailing windwhereby the vessel when headed into the wind will as nearly as possiblealways be at right angles to said line between said pair of towersupporting structures with its narrowest part in the direction of theline between said pair of structures and its bow and stern far removedfrom said pair of structures and said platform supporting structure, ahigh line supported on said towers running over the platform and overthe amidships section of the vessel where the vessel is most nearlystationary, a skip supported on the high line, and means to move theskip up and down and along the high line between the vessel and platformwhereby men and materials can be conveyed between said vessel andworking platform in all weather except severe storms and hurricanes,said towers supporting the highline above the highest point of thevessel whereby the vessel is entirely clear thereof and can be movedfreely therebeneath when the skip is raised away therefrom, said mooringmeans being releasable whereby the vessel can be moved out of the pathof a storm, said structures for supporting said platform and towersbeing of openwork construction to allow high velocity fluids to passtherethrough without damage to said structures.

ROSS WHITE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 89,794 Rowland May 4, 1869281,446 Brown July 17, 1883 387,794 McDonald Aug. 14, 1888 551,506Miller Dec. 17, 1895 676,626 I-Ioshor June 18, 1901 726,685 HolbrookApr. 28, 1908 874,223 Miller Dec. 17, 1907 919,178 Johnston Apr. 20,1909 949,961 Morris Feb. 22, 1910 2,512,783 Tucker June 27, 1950

